   import 'package:flutter/material.dart';

   class DemoPage extends StatelessWidget {
     const DemoPage({Key key}) : super(key: key);
   
     @override
     Widget build(BuildContext context) {
      return Scaffold(
        appBar: AppBar(
          title: Text('Demo'),
        ),
        body: Padding(
          padding: EdgeInsets.all(20),
          child: Column(
            children: <Widget>[
              Row(
                children: <Widget>[
                  
                ],
              )
            ],
          ),
        ),
       );
     }

     
   }